In the past, as a gas shutoff device of this type, a gas shutoff device including a flow measurement unit for outputting a flow signal corresponding to the amount of gas passing through, an individual appliance estimation unit for estimating an increase/decrease of the use of an individual appliance when the flow signal is increased/decreased, and outputting an estimated individual calculation flow rate of the increased/decreased appliance and use time, an individual flow registration unit for registering a flow rate of an individual appliance being used in advance and outputting the registered individual flow rate and the use time, an individual flow storage unit for storing the registered individual flow rate, an abnormal flow determination unit for outputting an individual error signal in the case where the estimated individual calculation flow rate of the increased/decreased appliance is not included in the registered individual flow rate of the individual flow storage unit, and the continuous use time of the increased/decreased appliance is equal to or longer than a first predetermined time, a notification unit for producing a warning notification regarding an error in gas flow rate, or a shutoff unit for shutting a gas passageway on the basis of receiving the individual error signal, and an ordinary individual flow registration unit for registering the estimated individual calculation flow rate of the individual flow estimation unit in the individual flow storage unit in the case where the estimated individual calculation flow rate of the appliance of the individual appliance estimation unit is not included in the registered individual flow rate of the individual flow storage unit, and the use time of the appliance of the individual appliance estimation unit is longer than a second predetermined time and shorter than the first predetermined time, is disclosed (for example, refer to Patent Document).
When the gas shutoff device of Patent Document 1 is briefly described with reference to FIG. 5, reference numeral 101 denotes a flow measurement unit as a flow sensor mounted to a gas meter. Reference numeral 102 denotes an individual appliance estimation unit for calculating a flow signal s of a flow sensor 1 as an average flow rate of a predetermined measurement period (30 seconds), estimating an increase/decrease in the individual flow rate in use on the basis of the increase/decrease in the average flow rate, and outputting an estimated individual calculation flow rate Q of the increased/decreased appliance and a use time. This individual appliance estimation unit 102 determines that a gas appliance is used on the basis of the increase when the average flow rate increases, and determines that the gas appliance is stopped on the basis of the decrease in the case where the average flow rate decreases, to estimate the usage of the individual appliance. Reference numeral 103 denotes an individual flow registration unit as a setting unit for inputting a flow rate (Qi) of an individual appliance used at home in advance. Reference numeral 104 denotes an individual flow storage unit for storing the flow rate (Qi) of the individual appliance of the individual flow registration unit 103 and flow rates of the ordinary individual flow registration unit 107 sequentially as Q1, Q2, Q3, . . . , Qn. Reference numeral 105 denotes an abnormal flow determination unit for outputting an individual error signal E when the estimated individual flow rate Q output from the individual appliance estimation unit 102 is not included in {Q1, Q2, Q3, . . . , Qn} of the individual flow storage unit 104 and the estimated individual flow rate Q is continued for more than the first predetermined time (10 minutes). Reference numeral 106 denotes a notification unit or a shutoff unit including an LCD or an LED for giving a warning notification or a shutoff valve for shutting the gas passageway on the basis of receiving the individual error signal E. Reference numeral 107 denotes an ordinary individual flow registration unit for outputting the estimated individual flow rate Q to the individual flow storage unit 104 in the case where the estimated individual flow rate Q output from the individual flow estimation unit 102 is the second predetermined time (3 minutes) or more or the first predetermined time (10 minutes) or less.
Next, the operation of the configuration of the prior example will be described. An average flow rate is calculated on the basis of the flow signal of the flow measurement unit 101. A change in flow rate between the average flow rate and an average flow rate at the time before last measurement is obtained to determine whether the change is an increase or a decrease, and an estimated individual calculation flow rate Q is obtained by a corresponding process. It is determined whether or not the estimated individual calculation flow rate Q that newly appears as a result of the increase/decrease process is included in the individual flow storage unit 104, or used for the first predetermined time (10 minutes). When it is not included and it is used for 10 minutes or more, the notification unit or the shutoff unit 106 is operated. When it is not included or not used for 10 minutes or more, it is determined whether or not it is a non-registered flow rate, it is used for 3 minutes or more, the use time is 10 minutes or less, and when all are in conformity, the ordinary individual flow registration unit 107 performs registration processing on the individual flow storage unit 104.
Now, in the case where there is an increase in average flow rate as Qt (for example, Q2+Q3) due to the simultaneous use of a plurality of appliances, and the use time is for example 7 minutes, that is, the average flow rate decreases after 7 minutes, an estimated individual flow rate Qt is output from the individual appliance estimation unit 102. This estimated individual flow rate Qt is registered in the individual flow storage unit 104 by the ordinary individual flow registration unit 107 such that the use time is equal to or longer than 3 minutes or equal to or less than 10 minutes. Thereafter, it is registered in the individual flow registration unit 104, so that there is no shutoff even though the flow rate appears for 10 or more minutes. That is, error shut-off caused by gas appliances that start operating at the same time in many cases can be reduced. In addition, in the case where there is a new individual flow rate Qk (3 minutes or longer or 10 minutes or less) due to appliance replacement, an estimated individual flow rate Qk is output from the individual appliance estimation unit 102. The estimated individual flow rate Qk is registered in the individual flow storage unit 104 by the ordinary individual flow registration unit 107 such that the use time is 3 minutes or longer or 10 minutes or less.
Thereafter, since it is registered in the individual flow storage unit 104, there is no shutoff even though the flow rate appears for 10 or more minutes. Individual appliances used at each home are stored in advance, and accidents caused by gas leakage due to a flow rate other than the individual appliances can be prevented in advance, and error shutoff caused by the simultaneous start of the appliances or appliance replacement can be prevented.
In addition, as illustrated in FIG. 6, there is provided a flow measurement unit 1 for outputting a flow signal according to the amount of gas passing through, an individual appliance calculation unit 2 for calculating an average flow rate for a predetermined period upon receiving the flow signal transmitted from the flow measurement unit 1, calculating an increase/decrease in the appliance in use by calculating an increase/decrease in the average flow rate at predetermined times, and outputting the calculation flow rate of the increased/decreased appliance, an individual appliance registration unit 6 for registering the calculation flow rate of the increased/decreased appliance and outputting a maximum individual calculation flow rate, and a shutoff unit for receiving the maximum individual calculation flow rate, receiving an individual error signal from the abnormal flow determination unit for outputting the individual error signal in the case where the continuous use time of the appliance continues for a predetermined time or more, and outputting a shutoff signal to the gas passageway. The flowchart of flow rate registration and flow rate deletion procedures of the individual appliance registration unit 6 is illustrated in FIG. 7 (for example, refer to Patent Document 2).
[Patent Document 1] JP-A-7-44239
[Patent Document 2] JP-A-5-134762